Rio Tinto Opens Underground Mine at Argyle

The new Argyle underground diamond mine in Western Australia has been opened, says miner Rio Tinto.

The change to an underground mining operation from open pit mining guarantees mining at Argyle until at least the year 2020.

Average annual output during the lifespan of the underground mine is forecast to be 20 million carats, Rio Tinto said in a statement.

The mining giant said the $2.2 billion underground mine is using modern block caving technology.

Rough diamond production from the Argyle mine over the past quarter century totals around 800 million carats, of which a small but consistent supply has been and continues to be of rare pink diamonds.